Elastic-fluid turbine.



No. 807,642. PATENTED DEC. 19, 1905.

0. G. CURTIS. ELASTIC FLUID TURBINE.

APPLICATION FILED MAY 12, 1903.

mZ/z 66666 I 7 %4/LW -UNITED STATES PATENT OFFICE.

CHARLES CURTIS, OF NEW YORK, N. Y., ASSIGNOR, BY MESNE ASSIGN- MENTS, TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELASTIC-FLUID TURBINE.

Specification of Letters Patent.

Patented Dec. 19, 1905.

To all whom it may concern.-

Be it known that I, CHARLES G. OURrIs, a

citizen of the United States, residing in the borough of Manhattan, city of New York, State of New York, have invented a certain new and useful Improvement in Elastic-Fluid Turbines, of which the following is a specification.

The object I have in view is to construct the moving and stationary vanes of an elastic-fluid turbine so as to give the vane-passages the proper angles for receiving and discharging the fluid in an effective manner and to provide for the proper enlargement of the fluid passage-way 1n the direction of flow and at the same time to decrease the cost of cutting the vanes or buckets. In my Patent No: 566,968 I describe a construction in which the proper angles of entrance and discharge are produced by constructing both the mov-' ing and stationary vane passages with a less angle at the discharging end than at the receiving end, the progressive enlargement or expansion of the fluid passage-way in the di-' rection of the exhaust being produced by the divergence of the top and bottom walls of the vane-passages and by the progressive enlargement of the angles of entrance and dis' charge therefrom. This construction results in the production of unsymmetrical vane passages in the sense that the space between the side walls is greater at the receiving than at the discharging ends of the vane-passages, such side walls not being parallel. -In cut ting the vane-passages out of solid stock by means of slottlng-machines the unsymmetrical vane-passages cannot be cut at one operation, but a second out has to be made in order to secure the result. This increases largely the expense of cutting the vane-passages, an expense which is considerable on account of the large number of such passages. I have found that a satisfactory result can be secured if the unsymmetrical form is limited to the stationary intermediate vanes, the moving vanes being symmetrical in form and being cut at one operation. Since the sets of stationary intermediate vanes are always one less in number than the sets of moving vanes and since the intermediate vanes occupy only a part of the circumferential space, it is obvious that the expense of cutting the vane-passages will be greatly reduced if the second cutting operation is performed only on the st ationary intermediate vanes.

In the accompanying drawings, Figure 1 is an end view of a portion of the moving andstationary vanes of the turbine developed in a plane and embodying my present invention, the angles of entrance and discharge being indicated. Fig. 2 is a diagram representing the radial enlargement or expansion of the vane-passages; and Fig. 3 is a view similar to Fig. 1 of one of the stationary intermediate vane-passages, showing in full lines the symmetrical form of the passage produced by the first cut and in dotted lines the unsymmetrical form produced by the second cut, the angles before and after the second cut is made being indicated.

A, B, andOare sets of movable vanes which, as will be understood, are mounted upon the periphery of a wheel and occupy its entire circumference. D and E are sets of stationary intermediate vanes which, as will be understood, are supported by the casing and occupy only part of the circumference. The vane-passages between the vanes of the moving sets A, B, and O are symmetrical in form. In other words, the side walls in the vanes of each set are the same distance apart or parallel throughout the length of their opposing portions and the angles of entrance and discharge are the same for each set of vanes. These angles of entrance and discharge are, however, made successively greater toward the exhaust, as will be understood by reference to my patent already referred to. The vane-passages of the moving vanes can therefore be cut from solid stock by a single succession of cuts at one operation. The inter mediate stationary vanes, however, are produced by first cutting the vane-passages in symmetrical form or with parallel opposing side walls, as shown in full lines in Fig. 3, and by then making a second series of cuts on the front wall of each vane-passage, as illustrated by the dotted line a in Fig. 3. In this way the stationary intermediate vane passages can be given a greater angle at their receiving ends than at their discharging ends, the difference in angle produced by the second series of cuts being indicated in Fig. 3. Due to the forward motion of the moving vanes the elastic fluid is discharged from the moving-vane passages at a greater angle than the angle of such passages at their discharge ends, and to receive the fluid effectively from the movingvanes the stationary vanes must have an angle which corresponds closely to the angle at which the fluid is discharged from the moving vanes; but in order that the fluid may be effectively utilized in the next set of moving vanes the angle of discharge from the stationary-vane passages must be lessened or made sharper than the angle of entrance. This result is accomplished by the employment of the unsymmetrical stationary-vane passages and is particularly important in a turbine using a number of sets of moving vanes, because otherwise the angle at which the fluid is delivered to the moving vanes would soon become so great as to make its action upon such vanes ineffective. The enlargement or expansion of the fluid-passage in the direction of the exhaust, notwithstanding the contraction produced by the enlargement of each set of stationary vane-passages in the opposite direction, is secured by the progressively-greater angles of entrance and discharge of the moving and stationary vanes, as illustrated in Fig. 1, and by the divergence of the top and bottom walls of the vane-passages, as illustrated in Fig. 2.

It will be understood that the jet of elastic fluid is delivered to the moving vanes A and passes in succession through the stationary and moving vanes D B E O to the exhaust of the turbine. It should also. be understood that any number of sets of moving vanes greater than one can be employed with an appropriate number of intermediate stationary vanes.

The angles of entrance and discharge on the several sets of vanes are shown in Fig. ,1 of the drawings to illustrate an actual case embodying the invention. The stationary intermediate vane passages may have longer discharging than receiving ends, as illustrated; but this is not essential.

What I claim is I 1. In an elastic-fluid turbine, the combination of two or more sets of movable-vane passages and one or more sets of stationary intermediate vane passages, the movablevane passages having parallel opposing side walls, and the stationary intermediate vane passages having non-parallel opposing side walls, substantially as set forth.

2. In an elastic-fluid turbine, the combination of two or more sets of movable-vane passages and one or more sets of stationary intermediate vane passages, the movablevane passages having parallel opposing side walls and the stationary intermediate vane seam passages having opposing side walls which diverge toward their receiving ends, substantially as set forth.

3. In an elastic-fluid turbine, the combinationof two or more sets of movable-vane passages and one or more sets of stationary intermediate vane passages, the movablevane passages of each set having the same angles of entrance and discharge, and the stationary intermediate vane passages of each set having different angles of entrance and discharge, substantially as set forth.

4. In an elastic-fluid turbine, the combination of two or more setsof movable-vane passages and one or more sets of stationary intermediate vane passages, the movablevane passages of each set having the same angles of entrance anddischarge, and the stationary intermediate vane passages of each set having a greater angle of entrance than of discharge, substantially as set forth.

5.- In an elastic-fluid turbine, the combination of two or more sets of movable-vane passages having parallel opposing side walls, and one or more sets of stationary intermediate vane passages having non-parallel opposing side walls, the vane passages increasing or expanding in crosssectional area toward the exhaust, substantially as set forth.

6. In an elastic-fluid turbine, the combination of 'tWo or more sets of movable-Vane passages, the vane passages of-each of such sets having the same angle of entrance and discharge, and one-or more sets-of-stationary intermediate vane passages, the vane passages of each of such sets having a greater angle of entrance than ofdischarge,'the.angles of entrance and discharge in all the vane passages increasing progressively toward the exhaust, substantially as set forth.

7. In an elastic-fluid turbine, the combination of two or more sets of movable-vane passages, the vane passages of eachof such sets having the same angle of entrance and discharge, and one or more sets of stationary intermediate vane passages, the vane passages of each of such sets having a greater angle of entrance than of discharge, the angles of entrance and discharge in all the vane passages increasing progressively toward the exhaust, and the vane passages also increasing IIO 

